Organic device, display apparatus, image capturing apparatus, illumination apparatus, and moving body

ABSTRACT

An organic device comprising a reflective electrode, an organic layer arranged on the reflective electrode, a semi-transmissive electrode arranged on the organic layer and a reflection surface formed above the semi-transmissive electrode is provided. The organic layer emits white light and includes a blue-emitting layer. An optical distance L of the organic layer satisfies L≥[{(ϕr+ϕs)/π}×(λb/4)]×1.2, where λb is a peak wavelength of the blue-emitting layer, ϕr and ϕs are a phase shift of the wavelength λb in the reflective electrode and the semi-transmissive electrode, respectively. A resonant wavelength of an optical distance between the semi-transmissive electrode and the reflection surface is shorter than the wavelength λb.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to an organic device, a display apparatus,an image capturing apparatus, an illumination apparatus, and a movingbody.

Description of the Related Art

An organic device that includes an organic EL light emitting element hasgained attention. There is known a method (to be referred to as awhite+CF method hereinafter) that uses a light emitting element whichemits white light and a color filter to increase the resolution of anorganic device. Since an organic layer is deposited on the entiresurface of a substrate in the white+CF method, the resolution can beincreased easily by adjusting the pixel size, the pitch between thepixels, or the like compared to a method in which the organic layer isdeposited for each color by using a metal mask.

In Japanese Patent Laid-Open No. 2011-210677, there is disclosed that aplurality of optical path adjustment layers for adjusting lightinterference will be arranged on a semi-transmissive electrode on alight-extraction side to make, with respect to a wavelength λ of a lightbeam to be extracted, the optical distance between a light emittinglayer and an optical path adjustment layer be an integer multiple ofλ/4.

Since it is difficult to optimize the light extraction structure foreach color in the white+CF method, the light extraction efficiency maydecrease. Hence, the film thickness of an organic layer which includesthe light emitting layer is decreased to reduce a driving voltage sothat high-luminance display can be performed, as a result, by the samevoltage. When the film thickness of organic layer is to be decreased,the film thickness of the organic layer can be designed to have a filmthickness that can cause interference (resonance) for strengtheninglight to occur by using optical interference, and be designed to have aminimum order of interference for film thickness reduction. Since thechromaticity of a blue pixel strongly depends on the film thickness ofthe organic layer, the film thickness of the organic layer fordisplaying deep blue needs to be 75 nm or less in a case in which theminimum order of interference is to be used. However, if the filmthickness of the organic layer is decreased to be about 100 nm or less,leakages and short circuits due to unevenness caused by a foreign objector the like may increase exponentially, and the yield will decrease insome cases.

If the film thickness of the organic layer is increased to improve theyield, the optical path adjustment layer disclosed in Japanese PatentLaid-Open No. 2011-210677 cannot modulate the shift in the interferencecondition caused by the increase in the film thickness of the organiclayer. Thus, it may reduce the chromaticity. That is, it is difficult toimprove both the yield and the color reproducibility by using thestructure disclosed in Japanese Patent Laid-Open No. 2011-210677.

SUMMARY OF THE INVENTION

Some of the embodiments of the present invention will provide atechnique advantageous in implementing both an improvement inreliability and an improvement in color reproducibility of an organicdevice.

According to some embodiments, an organic device comprising a reflectiveelectrode configured to reflect light, an organic layer arranged on thereflective electrode, a semi-transmissive electrode arranged on theorganic layer, and a reflection surface formed above thesemi-transmissive electrode, wherein the organic layer emits white lightand includes a light emitting layer configured to emit blue light, anoptical distance L of the organic layer satisfiesL≥[{(ϕr+ϕs)/π}×(λb/4)]×1.2 where λb [nm] is a peak wavelength of emittedlight of a blue light emitting layer, ϕr [rad] is a phase shift amountof the light of the wavelength λb in the reflective electrode, ϕs [rad]is a phase shift amount of the light of the wavelength λb in thesemi-transmissive electrode, and a resonant wavelength of an opticaldistance between the semi-transmissive electrode and the reflectionsurface is shorter than the wavelength λb, is provided.

According to some other embodiments, an organic device comprising areflective electrode configured to reflect light, an organic layerarranged on the reflective electrode, a semi-transmissive electrodearranged on the organic layer, and an interference adjustment layerarranged on the semi-transmissive electrode, wherein the organic layeremits white light and includes a light emitting layer configured to emitblue light, the interference adjustment layer includes a first layer incontact with the semi-transmissive electrode, a second layer arranged onthe first layer, and a third layer arranged on the second layer, thefirst layer is made of an element selected from the group consisting ofsilicon nitride, silicon oxynitride, titanium oxide, zinc sulfide, andindium tin oxide, the second layer is made of an element selected fromthe group consisting of magnesium fluoride, lithium fluoride, afluoropolymer, silver, magnesium, and combinations thereof, the thirdlayer is made of an element selected from the group consisting ofsilicon oxide, silicon nitride, silicon oxynitride, and aluminum oxide,a film thickness of the organic layer is not less than 85 nm, a filmthickness of the first layer is not more than 50 nm, and a filmthickness of the second layer is not less than 10 nm and not more than300 nm, is provided.

According to still other embodiments, an organic device comprising areflective electrode, an organic layer arranged on the reflectiveelectrode, a semi-transmissive electrode arranged on the organic layer,and a reflection surface formed above the semi-transmissive electrode,wherein the organic layer emits white light and includes a lightemitting layer configured to emit blue light, a resonant wavelength ofthe organic layer is not less than 510 nm and not more than 550 nm, aresonant wavelength of an optical distance between the organic layer andthe reflection surface is not more than 435 nm, and a minimum value ofoptical interference of the optical distance between the organic layerand the reflection surface is not less than 480 nm and not more than 510nm, is provided.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments (with reference to theattached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view schematically showing an example of thearrangement of an organic device according to this embodiment;

FIG. 2 is a perspective view of a display apparatus using the organicdevice according to FIG. 1;

FIG. 3 is a graph showing a PL spectrum of the organic device accordingto FIG. 1;

FIG. 4 is a graph showing transmittances of color filters of the organicdevice according to FIG. 1;

FIG. 5 is a graph showing relationship between a coefficient A of anorganic layer and a chromaticity v′ of a B pixel of the organic deviceaccording to FIG. 1 and those of organic devices according tocomparative examples;

FIG. 6 is a graph showing the relationship between the coefficient A ofan organic layer and the chromaticity v′ of a B pixel of each organicdevice according to FIG. 1;

FIG. 7 is a graph showing the relationship between the coefficient A ofthe organic layer and a coefficient B of a first layer of each organicdevice according to FIG. 1;

FIG. 8 is a graph showing the relationship between the coefficient A ofthe organic layer and the coefficient B of a second layer of eachorganic device according to FIG. 1;

FIG. 9 is a graph showing the wavelength dependence of reflectances andresonant intensities of the organic devices according to the comparativeexample;

FIG. 10 is a graph showing the wavelength dependence of reflectances andresonant intensities of the organic device of the organic device of FIG.1 and that of the organic device of the comparative example;

FIG. 11 is a graph showing the relationship between the coefficient A ofthe organic layer and a refractive index difference between the firstlayer and the second layer of the organic device of FIG. 1;

FIG. 12 is a graph showing the relationship between power consumptionand the refractive index difference between the first layer and thesecond layer of the organic device of FIG. 1;

FIG. 13 is a graph showing the relationship between a coefficient A ofan organic layer and a chromaticity v′ of a B pixel of each organicdevice according to FIG. 1 and that of an organic device according to acomparative example;

FIG. 14 is a graph showing the relationship between the coefficient A ofthe organic layer and a coefficient C of a first layer of each organicdevice according to FIG. 1;

FIG. 15 is a graph showing the wavelength dependence of reflectances andresonant intensities of the organic device according to FIG. 1 and thatof the organic device according to the comparative example;

FIG. 16 is a graph showing the relationship between power consumptionand a refractive index of the first layer of each organic deviceaccording to FIG. 1;

FIG. 17 is a graph showing exciton dissipation energy expressing surfaceplasmon loss in each organic device according to FIG. 1;

FIG. 18 is a table showing film thicknesses of respective components andexciton generation ratios of the organic device according to FIG. 1;

FIG. 19 is a table showing refractive index of the interference layer ofeach organic device according to FIG. 1 and that of each organic deviceaccording to the comparative example;

FIG. 20 is a table showing the refractive index of the interferencelayer of each organic device according to FIG. 1;

FIG. 21 is a table showing the relationship between the coefficient A ofthe organic layer, the coefficient B of the first layer, the coefficientB of a second layer, and the chromaticity v′ of the B pixel of theorganic device according to FIG. 1 and that of each organic deviceaccording to the comparative example;

FIG. 22 is a table showing the relationship between the coefficient A ofthe organic layer, the coefficient C of the first layer, and thechromaticity v′ of the B pixel of the organic device according to FIG. 1and that of the organic device according to the comparative example;

FIG. 23 is a view showing an example of a display apparatus using theorganic display device according to FIG. 1;

FIG. 24 is a view showing an example of an image capturing apparatususing the organic device according to FIG. 1;

FIG. 25 is a view showing an example of a portable device using theorganic device according to FIG. 1;

FIGS. 26A and 26B are views each showing an example of a displayapparatus using the organic device according to FIG. 1;

FIG. 27 is a view showing an example of an illumination apparatus usingthe organic device according to FIG. 1; and

FIG. 28 is a view showing an example of an automobile using the organicdevice according to FIG. 1.

DESCRIPTION OF THE EMBODIMENTS

Hereinafter, embodiments will be described in detail with reference tothe attached drawings. Note, the following embodiments are not intendedto limit the scope of the claimed invention. Multiple features aredescribed in the embodiments, but limitation is not made an inventionthat requires all such features, and multiple such features may becombined as appropriate. Furthermore, in the attached drawings, the samereference numerals are given to the same or similar configurations, andredundant description thereof is omitted.

The structure of an organic device according to embodiments of thepresent invention will be described below with reference to FIGS. 1 to22. FIG. 1 is a sectional view showing the structure of an organicdevice 100 according to this embodiment. FIG. 2 is a perspective viewschematically showing the arrangement of one embodiment of a displayapparatus 80 using the organic device 100. The organic device 100includes a plurality of light emitting elements 10. A section takenalong a line A-A′ shown in FIG. 2 is the sectional view shown in FIG. 1,and a single pixel for color display is formed by three light emittingelements 10 of the display apparatus 80. When specifying each lightemitting element 10, a suffix will be added following the referencenumber as in the manner of the light emitting element 10″R″. Thisdenotation will be performed in the same manner for other components aswell. Although the light emitting elements 10 are in a stripearrangement in the examples shown in FIGS. 1 and 2, a delta arrangementor a square arrangement may be used.

Each of the plurality of light emitting elements 10 includes areflective electrode 20 that is arranged on a substrate 1 and reflectslight, an organic layer 30 arranged on the reflective electrode 20, asemi-transmissive electrode 40 arranged on the organic layer 30, and aninterference adjustment layer 50 that is arranged on thesemi-transmissive electrode 40 and has a multilayer structure. Eachlight emitting element 10 according to this embodiment is a top-emissiontype light emitting element that extracts light from thesemi-transmissive electrode 40 arranged with respect to the reflectiveelectrode 20 with the organic layer 30 sandwiched between them. Theorganic layer 30, which is to be described later, emits white light. Theinterference adjustment layer 50 has a multilayer structure formed ofthree or more layers. In the arrangement shown in FIG. 1, theinterference adjustment layer 50 has a three-layer structure including afirst layer 51 which is in contact with the semi-transmissive electrode40, a second layer 52 which is arranged on the first layer 51 and incontact with the first layer 51, and a third layer 53 which is arrangedon the second layer 52 and in contact with the second layer 52. In thisembodiment, the third layer 53 functions as a sealing layer forprotecting the organic layer 30 from moisture or the like included inthe atmosphere.

The organic device 100 includes color filters 60 arranged on theinterference adjustment layer 50. The color filters 60 include, as shownin FIG. 1, color filters 60R, 60G, and 60B that transmit red light,green light, and blue light, respectively. As a result, the organicdevice 100 can form a display apparatus that performs color display.

A metal material whose reflectance with respect to the wavelength ofemitted light of the organic layer 30 is equal to or more than 80% canbe used as the reflective electrode 20. More specifically, a metal suchas aluminum (Al) or the like or an alloy obtained by adding a metal suchas Al to silicon (Si), copper (Cu), nickel (Ni), neodymium (Nd), or thelike can be used. Although details will be described later, to employ alowest-order interference structure that can increase the lightintensity of blue light of a wavelength of about 450 nm, a metal such asAl or the like whose plasmon frequency is in the ultraviolet region canbe used, from the point of view of surface plasmon loss, as thereflective electrode 20. For example, silver (Ag) or a silver alloy willincrease surface plasmon loss, the reflective electrode 20 need notcontain Ag.

The reflective electrode 20 can also be a multilayer film which is madeby layering an Al which has a high reflectance, an AL alloy, and abarrier metal. A material with a high hole-injection property can beused as the barrier metal. More specifically, metals such as titanium(Ti), tungsten (W), molybdenum (Mo), gold (Au), or the like or alloysthereof can be used. The barrier metal can be formed by, for example,sputtering or the like. When the barrier metal is to be formed, oxidefilm formation on the surface of a metal, such as Al on which an oxidefilm can be formed easily, can be suppressed, and thus an increase inthe voltage to be applied to the reflective electrode 20 can besuppressed.

The organic layer 30 includes a hole injection transport layer 31, alight emitting layer 32 containing an organic light emitting material,and an electron injection transport layer 33. Hence, the light emittingelement 10 can be an organic EL light emitting element. Each of the holeinjection transport layer 31 and the electron injection transport layer33 may have a single layer structure or may have a multilayer structureformed by a plurality of layers.

In this embodiment, the light emitting layer 32 is a light emittinglayer that emits white light. The light emitting layer 32 may be formedby a single layer or a plurality of layers. Although the arrangementshown in FIG. 1 shows an arrangement in which the light emitting layer32 is formed by layering a light emitting layer 32 a and the lightemitting layer 32 b, three or more light emitting layers may beincluded. In a case in which the light emitting layer 32 is to have amultilayer structure, the plurality of light emitting layers may be incontact with each other or a non-light emitting intermediate layer maybe sandwiched between the layers.

As shown in FIG. 1, in a case in which the light emitting layer 32includes the two light emitting layers 32 a and 32 b, the light emittinglayer 32 a (or the light emitting layer 32 b) can be the light emittinglayer which contains a blue light emitting material, and the lightemitting layer 32 b (or the light emitting layer 32 a) can be the lightemitting layer which contains a green light emitting material and a redlight emitting material. Also, for example, the light emitting layer 32a (or the light emitting layer 32 b) may be the light emitting layerwhich contains the green light emitting material and the red lightemitting material, and the light emitting layer 32 b (or the lightemitting layer 32 a) may be the light emitting layer which contains theblue light emitting material. In addition, in a case in which the lightemitting layer 32 contains three light emitting layers, a light emittinglayer which contains the red light emitting material, the light emittinglayer which contains the blue light emitting material, and the lightemitting layer which contains the green light emitting material may beincluded separately. The light emitting layers may be arranged, from theside of the reflective electrode 20, in the order of the light emittinglayer which contains the red light emitting material, the light emittinglayer which contains the blue light emitting material, and the lightemitting layer which contains the green light emitting material.Alternatively, the light emitting layers may be arranged in an orderwhich is reverse of the aforementioned order, or the light emittinglayer which contains the blue light emitting material may be arranged atthe edge of the light emitting layer 32. Also, for example, theabove-described intermediate layer may be included between the lightemitting layer which contains the red light emitting material and thelight emitting layer which contains the blue light emitting material.

Each layer of the light emitting layer 32 may be formed by one type ofcompound or by a plurality of types of compounds. More specifically, thelight emitting layer 32 may contain a host compound and a guestcompound. The host compound is a compound with the highest weight ratioin the light emitting layer 32, and the guest compound is a maincompound (organic light emitting material) in charge of light emission.

A known organic compound can be used as the host. For example, anaphthalene derivative, a chrysene derivative, a pyrene derivative, afluorene derivative, a fluoranthene derivative, a metal complex, atriphenylene derivative, a dibenzothiophene derivative, a dibenzofuranderivative, and the like can be used as the host compound. The host canbe an organic compound made of one of these derivatives or an organiccompound obtained by combining a plurality of these derivatives. Anorganic compound containing naphthalene and pyrene, an organic compoundcontaining fluorene and pyrene, or an organic compound containingchrysene and triphenylene is suitable as the host compound.

The hole injection transport layer 31 can contain a known hole transportmaterial. For example, a naphthalene derivative, a phenanthrenederivative, a chrysene derivative, a pyrene derivative, a fluorenederivative, a fluoranthene derivative, a metal complex, a triphenylenederivative, a dibenzothiophene derivative, a dibenzofuran derivative,and the like can be used as the hole injection transport layer 31. Thehole injection transport layer 31 can contain an organic compound madeof one of these derivatives or an organic compound obtained by combininga plurality of these derivatives. The hole injection transport layer 31can also contain a nitrogen atom between each of the above describedderivatives. Diarylamine containing naphthalene and chrysene ordiarylamine containing fluorene and naphthalene is suitable as the holeinjection transport layer 31.

The semi-transmissive electrode 40 functions as a semi-transmissivereflection layer that has a property (that is, a semi-transmissivereflection property) of partially transmitting and partially reflectinglight which has reached the surface of the electrode. Thesemi-transmissive electrode 40 can be made of an alkali metal, analkaline earth metal, or an alloy containing these metals. Morespecifically, a metal such as magnesium, silver, or the like or an alloymainly containing magnesium and silver can be used as thesemi-transmissive electrode 40.

The third layer 53 of the interference adjustment layer 50 is a sealinglayer that protects the organic layer 30 from moisture as describedabove. The third layer 53 can have a single layer structure or amultilayer structure. The third layer 53 (sealing layer) can be made of,for example, silicon oxide (SiO₂), silicon nitride (SiN_(x)), siliconoxynitride (SiON), aluminum oxide (Al₂O₃), or the like. The third layer53 can be formed by, for example, vapor deposition, sputtering, atomiclayer deposition, or the like. A material, among the above-describedmaterials, in which the refractive index becomes 1.9 or more at awavelength λb (approximately 450 nm) (to be described later) can be usedas the third layer 53.

Each color filter 60 is a filter that cuts off light of a wavelengthother than light of an arbitrary wavelength emitted from the lightemitting layer 32, that is, a filter that transmits light of anarbitrary wavelength. Each color filter 60 can be formed by a knownmethod. As shown in FIG. 1, a color filter corresponding to the lightemission color of each light emitting element 10 can be included in eachlight element. In addition, from the point of view of protection of theorganic device 100, a protection layer (not shown) such as protectionglass can be arranged on each color filter 60.

In the embodiment, each light emitting element 10 is designed so thatthe emission light color will be controlled by optical interference andlight will radiate with higher efficiency in a front direction bysetting the film thickness of the organic layer 30 to have aparticularly high luminance in the front direction. In this case, thefront direction is the upward direction in FIG. 1. In addition, awavelength in which light radiation can be strengthened by opticalinterference may be referred to as a resonant wavelength hereinafter.

Interference (resonance) for strengthening radiation can be set byadjusting, with respect to light of a wavelength λ, a distance do from alight emission position of the light emitting layer 32 to a reflectionsurface of the reflective electrode 20 to d₀=iλ/4n₀ (i=1, 3, 5 . . . ).As a result, components in the front direction will increase in thelight radiation distribution of the wavelength λ, thus improving thefront surface luminance. In this case, no is an effective refractiveindex of the wavelength λ in the layer from the light emission positionto the reflection surface. In this embodiment, assume that therefractive index is the refractive index of a light of 450 nm.

Next, an optical distance Lr, for causing the light of the wavelength λto resonate, from the light emission position of the light emittinglayer 32 to the reflection surface of the reflective electrode 20 willbe described. In this case, an “optical distance” indicates the totalsum of products obtained between a refractive index n_(j) of each layerand a thickness d_(j) of each layer. For example, an optical distance Lof the organic layer 30 shown in FIG. 1 can be expressed as

$\begin{matrix}{L = {\sum{n_{j} \times d_{j}}}} \\{= {{n_{31} \times d_{31}} + {n_{32a} \times d_{32a}} + {n_{32b} \times d_{32b}} + {n_{33} \times d_{33}}}}\end{matrix}$The optical distance of each component other than the organic layer 30can be obtained by the total sum of products obtained between therefractive index n_(j) of each layer and the thickness d_(j) of eachlayer. In addition, since the luminance in the front surface directionwill be described in the above manner, the thickness d_(j) of each layercan be, as shown in FIG. 1, a thickness in the normal direction withrespect to the surface on which the reflective electrode 20 of thesubstrate 1 is formed.

Letting ϕr [rad] be a sum of a phase shift amount when the light of thewavelength λ is reflected by the reflection surface of the reflectiveelectrode 20, the optical distance Lr from the light emission positionof the light emitting layer 32 to the reflection surface on thereflective electrode 20 is expressed as followsLr=(2m−(ϕr/π))×(λ/4)=−(ϕr/π))×(λ/4)  (1)where m is a non-negative integer. In addition, ϕ is a negative value.In this embodiment, m=0 is set to use the lowest interference conditionin the point of view of driving voltage reduction of the organic device100. Letting ϕ=−π and m=0, Lr=λ/4. The condition of m=0 according to theabove-described equation may be described as a λ/4 interferencecondition hereinafter.

Next, letting ϕs [rad] be a sum of a phase shift amount when the lightof the wavelength λ is reflected by the reflection surface of thesemi-transmissive electrode 40, an optical distance Ls from the lightemission position on the light emitting layer 32 to the reflectionsurface (the surface (lower surface) of the semi-transmissive electrode40 on the side of the substrate 1) of the semi-transmissive electrode 40is expressed as followsLs=(2m′−(ϕs/π))×(λ/4)=−(ϕs/π))×(λ/4)  (2)where m′ is a non-negative integer.

Hence, the optical distance L of the whole organic layer 30 that causesthe light of the wavelength λ to resonate (strengthen) can be expressedas followsL=(Lr+Ls)=(ϕ/π)×(λ/4)  (3)where ϕ is a phase shift amount sum (ϕr+ϕs) obtained when the light ofthe wavelength λ is reflected by the reflective electrode 20 and thesemi-transmissive electrode 40. Equation (3) is an interference referredto as a “whole layer interference” of the organic layer 30, and is the(λ/4) interference condition that strengthens the light of wavelength λof the whole organic layer 30. In addition, the optical distance fromthe reflective electrode to the semi-transmissive electrode can be saidto be the optical distance of the whole organic layer 30. In this case,the optical distance can be from the reflection surface on thesemi-transmissive electrode side of the reflective electrode to thereflection surface on the reflective electrode side of thesemi-transmissive electrode.

In this embodiment, in the point of view of gamut expansion of thedisplay color of the organic device 100, the wavelength of the light tobe extracted will be set as the wavelength λb, which is the shortestwavelength among the peak wavelengths in the light emission spectrum ofthe blue light emitting layer. The wavelength λb is about 450 nm. Inthis case, assuming that the refractive index of the organic layer 30 isabout 1.7 to 2.0, the film thickness of the organic layer 30 will beabout 70 nm based on equation (3). If the film thickness of the organiclayer 30 is reduced to about 70 nm, the organic layer 30 may not be ableto cover small unevenness such as very small foreign objects andseparation films between the respective light emitting elements 10.Hence, leakages and short circuits may occur more frequently between thelight emitting elements 10. As a result of consideration, the inventorshave found that the yield of the organic device 100 will be degradedexponentially when the film thickness of the organic layer 30 is reducedto about 90 nm or less. Hence, the inventors have considered and found astructure that can increase the film thickness of the organic layer 30while maintaining the chromaticity of the blue light emitting pixel (tobe referred to as a B pixel hereinafter) by incorporating theinterference adjustment layer 50 (to be described later) which has amultilayered structure.

The λ/4 interference condition of the whole layer interference of theorganic layer 30 according to this embodiment can be expressed, withrespect to the wavelength λb which is the smallest wavelength in theblue spectrum, based on equation (3) as followsL=(ϕ/π)×(λb/4)×A  (4)where a coefficient A is an interference condition of the whole organiclayer 30, and is a coefficient that serves as an index representing howmuch larger the film thickness the organic layer 30 has increased thanthe λ/4 interference condition of the wavelength λb. From the point ofview of leakage and short circuit prevention described above, thecoefficient A may be set to 1.2 or more. In this case,L≥[{(ϕr+ϕs)/π}×(λb/4)]×1.2Also, the coefficient A may be set to 1.3 or more. In this case,L≥[{(ϕr+ϕs)/π}×(λb/4)]×1.3Furthermore, the coefficient A may be set to 1.35 or more. In this case,L≥[{(ϕr+ϕs)/π}×(λb/4)]×1.35The film thickness of the organic layer 30 can be, for example, 85 nm ormore based on the relationship between this coefficient A and therefractive index described above. In addition, the film thickness of theorganic layer 30 may be 90 nm or more. Furthermore, the film thicknessof the organic layer 30 may be 100 nm or more. By increasing the filmthickness of the organic layer 30, the yield will improve when the lightemitting elements 10 are to be manufactured.

However, as the coefficient A of equation (4) increases, the resonantwavelength that strengthens the light of a specific wavelength of theorganic layer 30 will shift to the long wavelength side from thewavelength λb. In a case in which the coefficient A is about 1.2, theresonant wavelength will strengthen the green region (λ=500 nm). As willbe described later, by using the interference adjustment layer 50 whichhas a multilayered structure according to this embodiment, the light ofthe wavelength λb of the blue region can be strengthened even if theorganic layer 30 has a film thickness in which the resonant wavelengthfalls in the green region.

The interference adjustment layer 50 will be described next. In thisembodiment, each of the first layer 51, the second layer 52, and thethird layer 53 included in the interference adjustment layer 50 isformed by a dielectric. Patent literature 1 discloses that the filmthickness of each layer of a dielectric multilayer film, when theresonant wavelength is set to λ, is set to a film thickness in which theoptical distance of each layer will be (2m−1)×λ/4 (m is a non-negativeinteger). However, in this embodiment, to increase the light of thewavelength λb with respect to the organic layer 30 in which the resonantwavelength is in the green region away from the wavelength λb, acondition that falls outside the setting condition from the filmthickness shown in patent literature 1 is necessary. Hence, in thisembodiment, an optical distance L1 of the first layer 51 will be set asL1=(λb/4)×B  (5)where a coefficient B is a coefficient that serves as an indexrepresenting how much the first layer 51 has shifted the resonantwavelength closer to the short wavelength side by the interferencecondition of the first layer 51 than the λ/4 interference condition ofthe wavelength λ. In addition, in this embodiment, m=0 will be set fromthe point of view of suppressing a change in the characteristics of theorganic device 100 due to the film change of the first layer 51. Thecoefficient B may be 0.9 or less. In this case,L1≤(λb/4)×0.9At this time, the above-described coefficient A can be 1.2 or more. Inaddition, the coefficient B can be 0.8 or less. In this case,L1≤(λb/4)×0.8At this time, the above-described coefficient A can be 1.3 or more.Furthermore, the coefficient B can be 0.75 or less. In this case,L1≤(λb/4)×0.75At this time, the above-described coefficient A can be 1.35 or more.

In addition, in this embodiment, a refractive index n₁ of the wavelengthλb of the first layer 51 can be higher than a refractive index n₂ of thewavelength λb of the second layer 52. Also, a refractive index n₃ of thewavelength λb of the third layer 53 can be higher than the refractiveindex n₂ of the wavelength λb of the second layer 52. Furthermore, aswill be described later, a difference between the refractive index n₁ ofthe wavelength λb of the first layer 51 and the refractive index n₂ ofthe wavelength λb of the second layer 52 can be 0.58 or more. Regardingthe material of the first layer 51, the second layer 52, and the thirdlayer 53, any material will be sufficient as long as the refractiveindex condition described above is satisfied, and an inorganic materialor an organic material may be used. More specifically, a material whichhas a high refractive index can be used as the material of each of thefirst layer 51 and the third layer 53. For example, an inorganicmaterial such as SiO₂ (which has a refractive index of about 1.5),SiN_(x) (which has a refractive index of about 1.9 to 2.1), SiON (whichhas a refractive index of about 1.6 to 2.0), titanium oxide (TiO₂)(which has a refractive index of about 2.5), indium tin oxide (ITO)(which has a refractive index of about 1.8 to 2.0), zinc sulfide (ZnS)(which has a refractive index of about 2.4), Al₂O₃ (which has arefractive index of about 1.8), or the like can be used or an organicmaterial such as a triamine derivative or the like can be used as thematerial of each of the first layer 51 and the third layer 53. Also, amaterial that has a low refractive index can be used as the material ofthe second layer 52. For example, an inorganic material such asmagnesium fluoride (MgF₂) (which has a refractive index of about 1.4),lithium fluoride (LiF) (which has a refractive index of about 1.4), orthe like or an organic compound (for example, fluoropolymer (which has arefractive index of about 1.1 to 1.4) or the like) can be used as thematerial of the second layer 52. A mixture of these materials can alsobe used as the material of the second layer 52.

Each layer included in the interference adjustment layer 50 need not belimited to a dielectric. A case in which each of the first layer 51 andthe third layer 53 is made of a dielectric and the second layer 52 ismade of a metal in the interference adjustment layer 50 will bedescribed next. The embodiment described above in which each layerincluded in the interference adjustment layer 50 is a dielectric will bereferred to as the “first embodiment”, and an embodiment to be describedbelow in which the second layer 52 is a metal will be referred to as“the second embodiment” in some case hereinafter.

Conventionally, letting λ be a wavelength (resonant wavelength) to bestrengthened, the film thickness of a first layer 51 provided between asemi-transmissive electrode 40 and a second layer 52 made of a metalwill be set to a film thickness which becomes (2m−1)*λ/e (m is anon-negative integer). However, in this second embodiment, to increasethe light of a wavelength λb with respect to an organic layer 30 inwhich the resonant wavelength is in the green region away from thewavelength λb as described above, an optical distance L1′ of the firstlayer 51 can be set asL1′=(λb/2)×C  (6)where a coefficient C is a coefficient that serves as an indexrepresenting how much the first layer 51 has been shifted closer to theshort wavelength side from the interference condition which increasesthe wavelength λb. The coefficient C can also be 0.8 or less. In thiscase, it can be expressed asL1′≤(λb/2)×0.8In this case, a coefficient A described above can be 1.2 or more.Furthermore, the coefficient C can be 0.7 or less. In this case, it canbe expressed asL1′≤(λb/2)×0.7.In this case, the coefficient A described above can be 1.3 or more.

In a case in which the second layer 52 is made of a metal, from thepoint of view of surface plasmon loss, a refractive index n₁ of thefirst layer 51 may be 1.6 or more. Regarding the material of the firstlayer 51 and a third layer 53, any material will be sufficient as longas the refractive index condition described above is satisfied, and aninorganic material or an organic material may be used. Morespecifically, an inorganic material, for example, SiN_(x), SiON, TiO₂,ITO, ZnS, or the like can be used or an organic material such as atriamine derivative or the like can be used as the material of each ofthe first layer 51 and the third layer 53.

The second layer 52 functions has a semi-transmissive reflection layerwhich has a property (that is, semi-transmission reflection property) oftransmitting one part of light that has reached the surface andreflecting the remaining other part of the light. Although Ag or analloy of Ag and magnesium (Mg) can be used as the material of the secondlayer 52, only Ag may be used from the point of view of absorption.However, since a film may coagulate after film formation when a thinfilm made of Ag is used, an alloy with another metal and a metal film,which is made of calcium (Ca) or the like and provided under (on theside of the first layer 51 of) the Ag film, may be arranged separatelyin the point of view of improving the coverage of the second layer 52.In this case, this stacked structure made of these metal films may bereferred to as the second layer 52.

The details of the embodiments have been described above. In a case inwhich the light of the peak wavelength λb which is the shortestwavelength of the blue emitted light is to be extracted, the filmthickness of an organic layer 30 is reduced to 70 nm so an organic filmwill not be able to cover small unevenness such as very small foreignobjects and separation films between respective light emitting elements10, and yield degradation will problematically occur. On the other hand,if the film thickness of the organic layer 30 is increased based on aλ/4 interference condition, the resonant wavelength will shift to thelong wavelength side and the chromaticity of a B pixel will deteriorate,thus degrading the color reproduction range. That is, there is a cleartradeoff relationship between the chromaticity of the B pixel and themaintenance of the yield due to increasing the thickness of the organiclayer 30. In each embodiment, an interference adjustment layer 50 whichhas a multilayer structure is arranged on a semi-transmissive electrode40. Furthermore, by setting the film thickness (optical distance) of afirst layer 51, of the interference adjustment layer 50, to have a filmthickness in which the resonant wavelength will be a wavelength shorterthan a minimum peak wavelength λb of blue emitted light, it has beenfound that the chromaticity of blue can be maintained regardless of theincrease in the film thickness of the organic layer 30. That is, theresonant wavelength of the optical distance between the organic layer 30and the reflection surface of the interference adjustment layer 50 whichis formed on the semi-transmissive electrode 40 will be made shorterthan the wavelength λb. The reflection surface of the interferenceadjustment layer 50 will be described here. As will be described later,it is considered that a second layer 52 has a smaller influence on lightextraction than the first layer 51, and a third layer 53 does not tocontribute to optical interference because it is thicker than thevisible light wavelength. Hence, the reflection surface of theinterference adjustment layer 50 which is formed on thesemi-transmissive electrode 40 and the organic layer 30 can be theinterface between the first layer 51 and the second layer 52 (to besometimes referred to as a reflection surface 54 hereinafter). As aresult, it has been found that the film thickness of the organic layer30 can be increased to maintain the yield, and that both the improvementof the reliability and the color reproduction range of an organic device100 can be implemented. Also, it is suitable to improve the chromaticityof blue to improve color reproducibility. Thus, for example, it may bearranged so that, in a case in which the light emission spectrum of theblue light emitting material has a first peak and a second peak which issmaller than the first peak, the minimum wavelength of the interferencespectrum of each light emitting element will be closer to the wavelengthof the second peak than the wavelength of the first peak. Thechromaticity of blue can be improved by setting an arrangement thatreduces the second peak.

The effects of each embodiment will be described next by using asimulation. FIG. 3 shows the PL spectrums of a red light emitting dopant(to be sometimes referred to as RD hereinafter), a green light emittingdopant (to be sometimes referred to as GD hereinafter), and a blue lightemitting dopant (to be sometimes referred to as BD hereinafter),respectively, which are used in each/the embodiment. Each PL spectrumhas been normalized at the maximum peak value. FIG. 4 shows therelationship between the transmittance and the wavelength of each ofcolor filters 60R, 60G, and 60B used in each embodiment. The PL spectrumof each color shown in FIG. 3 and the transmittance of each color filter60 shown in FIG. 4 are not limited to materials that have eachexemplified spectrum, and materials can be combined and used as neededin accordance with the characteristic of each light emitting element 10such as the gamut.

In each embodiment, a multi-objective optimization calculation wasperformed by using, as variables, the film thicknesses of thesemi-transmissive electrode 40, a hole injection transport layer 31, andan electron injection transport layer 33, respectively, and excitongeneration ratios γ_(b), γ_(g), and γr of BD, GD, and RD, respectively.FIG. 18 shows the film thickness of each charge transport layer and thelower limit and the upper limit of exciton generation ratios γ of BD andGD. In the following analysis, unless otherwise mentioned, a lightemitting layer 32 has as stacked arrangement formed by a light emittinglayer 32 a and a light emitting layer 32 b as exemplified in FIG. 1. Thelight emitting layer 32 a is a light emitting layer containing a mixeddopant with GD and RD (to be sometimes referred to as GD+RDhereinafter), and the light emitting layer 32 b is a light emittinglayer including BD. Each of the light emitting layer 32 a and the lightemitting layer 32 b has a film thickness of 10 nm. In each embodiment,the light emitting layer 32 suffices to include a light emitting layerthat emits blue light (a light emitting layer that includes BD) and toemit white light as the light emitting layer 32 overall. An appropriatestacking order and arrangement of the light emitting layer 32 can beused in accordance with the required performance of each light emittingelement 10. That is, for example, it may be arranged so that the lightemitting layer 32 a is doped with BD and the light emitting layer 32 bis doped with a mixture of GD and RD. 0.82 has been assumed here to bethe light emission yield in each of BD bulk, GD bulk, and RD bulk. Thelight emission yield in bulk is the light emission yield of the lightemitting dopant when optical interference is not present.

In addition, unless otherwise mentioned, a reflective electrode 20 ofthis analysis has a stacked structure made of Al/Ti. In this case,assume that the film thickness of Ti which is a barrier metal arrangedbetween Al and organic layer 30 is 10 nm. Assume that thesemi-transmissive electrode 40 is an MgAg alloy electrode. Also, asdescribed above, assume that the wavelength λb to be extracted is 450nm, and in a case in which the reflective electrode 20 is an Alelectrode (the Al/Ti stacked electrode will be sometimes simply referredto as the Al electrode hereinafter), the λ/4 interference condition ofequation (3) is about 145 nm. In addition, in a case in which thereflective electrode 20 is an Ag electrode, the λ/4 interferencecondition is about 135 nm. The coefficient A of the whole organic layer30 shown in equation (4) can be calculated from the λ/4 interferencecondition with respect to the optical distance L and the wavelength λbof the organic layer 30.

The optical simulation used a CSP method. The CSP method is a methodwell known in the field of organic EL. The multi-objective optimizationalgorithm was performed by NESA+, and a multi-objective optimizationcalculation was performed using an objective function in which thecoefficient A will have maximum value and a chromaticity v′ of the Bpixel will have a minimum value. A chromaticity u′>0.45 of the red lightemitting pixel (to be sometimes referred to as the R pixel hereinafter)and a chromaticity u′<0.13 of the green light emitting pixel (to besometimes referred to as the G pixel hereinafter) were set as constraintfunctions of the multi-objective optimization. Furthermore, the carrierbalance was assumed to be 1, and each exciton generation ratio γ wasadjusted so that the sum of the exciton generation ratios γ will be 1(γ_(b)+γ_(g)+γ_(r)=1).

In the calculation of the power consumption of the panel, the apertureratio of each pixel was set to 50%, and the aperture ratio of the lightemitting element 10 is uniformly set to 16.7% for each of red, green,and blue light emitting elements. Power necessary for the organic device100 having a panel size of 0.5 to emit white light of a colortemperature of 6,800 K at a luminance of 200 cd/cm² is calculated. Morespecifically, the chromaticity and the light emission efficiency ofwhite light were obtained to calculate the required current for each ofred light, green light, and blue light. In this analysis, the drivingvoltages was assumed to be 10 V, and the power consumption wascalculated from the required current value.

The analysis result of the first embodiment will be described first.First, it will be shown that the effect of the interference adjustmentlayer 50 having a multilayer structure can be first expressed by settinga three-layer arrangement. FIG. 5 shows a Pareto optimal solution of thecoefficient A and a chromaticity v′ of the B pixel with respect to thecombination of each layer of the interference adjustment layer 50 shownin FIG. 19. As shown in FIG. 19, reference symbol D100 denotes a lightemitting element of a comparative example in which the interferenceadjustment layer 50 which has a multilayer structure is absent (only thethird layer 53 functioning as the sealing layer is present), and each ofreference symbols D101 and D102 denotes a light emitting element of thecomparative example in which the second layer 52 is not arranged. Also,each value shown in FIG. 19 is a refractive index of each layer ofλb=450 nm. In this case, a light extinction coefficient κ has beenomitted because it is sufficiently small and does not influence theoptical characteristic. In addition, light emitting elements D110 andD111 are shown as examples of the first embodiment.

In FIG. 5, the calculation was performed by using exciton generationratios γ_(b), γ_(g), and γ_(r) of BD, GD, and RD, respectively, asvariables. That is, FIG. 5 shows the result in which the RGB lightemission ratios have been optimized so that the coefficient A will havea maximum value and the chromaticity v′ of the B pixel will have aminimum value.

As shown in FIG. 5, in the element D100 without the interferenceadjustment layer 50, the chromaticity v′ of the B pixel increases as thecoefficient A increases (that is, the total film thickness of theorganic layer 30 increases) so that the chromaticity v′ of the B pixelis 0.16 when the coefficient A=1 and the chromaticity v′ of the B pixelis 0.19 when the coefficient A=1.2. Considering that the chromaticity v′of the B pixel is 0.158 in sRGB, this result represents that the colorreproduction range is reduced as the value increases. That is, it showsthat there is a clear tradeoff relationship between the coefficient Aand the chromaticity v′ of the B pixel. In the following discussion, theindex value of the chromaticity of the B pixel will be assumed to bev′=0.160.

When v′=0.160 in the elements D101 and D102 which do not include thesecond layer 52, A=1.05 and A=1.1, respectively, and it can be seen thatthe increase in the coefficient A is small compared to the element D100which has the same chromaticity v′ of the B pixel. That is, in theelements D101 and D102, it can be seen that the tradeoff relationshipbetween the coefficient A and the chromaticity v′ of the B pixel is thealmost the same such as that of the element D100.

On the other hand, in the elements D110 and D111 according to theexamples of the first embodiment, the coefficient A=1.3 (D110) and thecoefficient A=1.25 (D111), respectively, when the chromaticity v′ of theB pixel is 0.160, and it can be seen that the coefficient A hasincreased more than the comparative examples in which the coefficient Ais 1.1 or less. That is, by arranging the first layer 51, the secondlayer 52, and the third layer 53 as the interference adjustment layer50, the tradeoff relationship between the coefficient A and thechromaticity v′ of the B pixel can change. As a result, the increase inthe chromaticity v′ of the B pixel can be suppressed even if the filmthickness of the organic layer 30 is increased, and it is possible toimprove the reliability to the organic device 100 and achieve goodchromaticity v′ of the B pixel.

The film thicknesses of the first layer 51 and the second layer 52expressing the effect of the embodiment will be described next. Thethird layer 53 generally has a film thickness of 1 μm or more tofunction has a sealing layer for maintaining a moisture resistanceproperty as described above. Since the third layer 53 is thicker thanthe visible light wavelength and can considered to be a non-interferencelayer which does not contribute to optical interference, a descriptionthereof will be omitted here.

FIG. 6 shows a Pareto optimal solution of the coefficient A and thechromaticity v′ of the B pixel of each of elements D112 to D114,according to the examples of the embodiment, obtained when therefractive index of each layer of the interference adjustment layer 50shown in FIG. 20 has been changed. Also, FIG. 7 shows the coefficient Bof the first layer 51 of the Pareto optimal solution element arrangementof FIG. 6. In this case, to clarify the relationship related to the filmthickness of the first layer 51, a calculation was performed by fixingthe exciton generation ratios of BD, GD, and RD to γ_(b)=0.48,γ_(g)=0.28, and γ_(r)=0.24, respectively.

In the elements D112, D113, and D114 shown in FIG. 6, the coefficientA=1.55 (D112), the coefficient A=1.38 (D113), and the coefficient A=1.25(D114), respectively, when the chromaticity v′ of the B pixel is 0.160.That is, for each of the elements D112, D113, and D114, it can be seenthat the coefficient A has increased more than D100 of the comparativeexample in which the coefficient A=1. That is, this represents that thefilm thickness of the organic layer 30 can be increased whilemaintaining the chromaticity v′ of the B pixel.

FIG. 7 shows the B coefficient of the first layer 51 according to thePareto optimal solution shown in FIG. 6. That is, the relationshipbetween the coefficient A of the organic layer 30 and the coefficient Bof the first layer 51 is shown. From FIG. 7, it can be seen that thecoefficient B of the first layer 51 is set to about 1 when thecoefficient A is 1. That is, the optimal film thickness of the firstlayer 51 is λb/4 in a case in which the film thickness of the organiclayer 30 is a film thickness based on the λb/4 interference condition.On the other hand, the optimal value of the coefficient B of the firstlayer 51 decreases when the coefficient A increases. That is, in a casein which the film thickness of the organic layer 30 is to become thickerthan the resonant wavelength of λb/4, the film thickness of the firstlayer 51 is preferably set so that the film thickness of the first layer51 will be smaller than the λb/4 optical condition. In other words, theresonant wavelength of the first layer 51 can be shorter than thewavelength λb. In this embodiment, if the coefficient A is to be set tobe 1.2 or more in the point of view of the yield, the coefficient B ofthe first layer 51 may be set to 0.9 or less based on the calculationresult of FIG. 7. In addition, it may be set so that the coefficient Aof the organic layer 30 will be 1.3 or more and the coefficient B of thefirst layer 51 will be 0.8 or less. The refractive index of theabove-described material used as the first layer 51 is about 1.5 to 2.4.Hence, based on the relationship between the coefficient B and therefractive index, the film thickness of the first layer 51 can be setto, for example, 50 nm or less. The film thickness of the first layer 51may also be set to 40 nm or less. As shown in FIG. 18, the filmthickness of the first layer 51 can be set to fall within a range of 10nm (inclusive) to 250 nm (inclusive). Furthermore, for example, amaterial whose refractive index is 1.6 or more such as SiN_(x), SiON,TiO₂, ITO, ZnS, or the like can be used for the first layer 51.

FIG. 8 shows the relationship between the coefficient A of the organiclayer 30 according to each Pareto optimal solution of FIG. 6 and thecoefficient B of the second layer 52 obtained from equation (4).Regarding second layer 52, the correlation with respect to thecoefficient A has a smaller influence than the first layer 51, and, forexample, the coefficient B of the second layer 52 may be set to be 0.6(inclusive) to 1.4 (inclusive). That is, the film thickness of thesecond layer 52 may be set to be smaller than the λb/4 optical conditionor may be set to be larger than the λb/4 optical condition. Therefractive index of each material described above which may be used forthe second layer 52 is about 1.3 to 1.5. Hence, based on therelationship between the coefficient B and the refractive index, thefilm thickness of the second layer 52 can be set to, for example, fallwithin the range of 10 nm (inclusive) to 300 nm (inclusive) as shown inFIG. 18.

FIGS. 9 and 10 are graphs illustrating the wavelength dependency of theresonant intensity of each light emitting element 10 according to theembodiment. FIG. 9 shows the calculation results of the wavelengthdependency of the resonant intensity of an element D100-a which does notinclude the first layer 51 and the second layer 52, and that of anelement D114-a in which the coefficient B of each of the first layer 51and the second layer 52 is 1 according to a comparative example. Also,FIG. 9 shows the calculation result of the wavelength dependency ofreflectance of light, which is emitted from the light emitting layer 32of the organic layer 30 and is obtained closer to the side of theinterference adjustment layer 50 than the organic layer 30, of theelement D100-a and that of the element D114-a. FIG. 10 shows thewavelength dependency of the resonant intensity of the element D100-aaccording to the comparative example and an element D114-b in which thecoefficient B of the first layer 51 is 0.64 according to an example ofthe embodiment. FIG. 10 also shows the calculation result of thewavelength dependency of reflectance of light, which is emitted from thelight emitting layer 32 of the organic layer 30 and is obtained closerto the side of the interference adjustment layer 50 than the organiclayer 30, of the element D100-a and that of the element D114-b. FIG. 21is a table summarizing the coefficient A of the organic layer 30, thecoefficient B of the first layer 51, and the coefficient B of the secondlayer 52 of each of the elements D100-a, D114-a, and D114-d. The filmthicknesses of the hole injection transport layer 31, the electroninjection transport layer 33, and the semi-transmissive electrode 40 ofthe light emitting element 10 have been calculated to be 20 nm, 54 nm,and 10 nm, respectively. In this case, the coefficient A of the organiclayer 30 will be 1.26. Also, the refractive indices at the wavelengthλb=450 nm of the first layer 51, the second layer 52, and the thirdlayer 53 are set to 2.2, 1.56, and 1.99, respectively. The coefficient Bof the first layer 51 of the element D114-a and that of the elementD114-b are 1.00 and 0.64, respectively, as described above.

First, in the element D100-a without the first layer 51 and the secondlayer 52, since an optical interference condition that strengthens thelight of the green region was set because the coefficient A of theorganic layer 30 is 1.26, the chromaticity v′ of the B pixel was 0.205.The chromaticity v′ of the B pixel of the element D114-a according tothe comparative example in which the coefficient B of the first layer 51is 1.0 was 0.188. On the other hand, the chromaticity v′ of the B pixelof the element D114-b according to the example of the embodiment was0.160. As described above, it has been found that, in an light emittingelement in which the value of the coefficient A of the organic layer 30is large, the chromaticity v′ of the B pixel can be improved by reducingthe coefficient B of the first layer 51.

As shown in FIG. 9, in the element D100-a, the wavelength of theresonant intensity between the reflective electrode 20 and thesemi-transmissive electrode 40 increases as the coefficient A of theorganic layer 30 increases (the film thickness increases), and becomesan optical interference that strengthens the light of a wavelength ofabout 500 nm at A=1.26. Also, since the coefficient A of the organiclayer 30 is 1.26 in the element D114-a, it can be seen that the resonantintensity between the reflective electrode 20 and the semi-transmissiveelectrode 40 has a resonant wavelength near the wavelength of 500 nm ina similar manner. FIG. 9 further shows the reflectance of the light,which is emitted from the light emitting layer 32 of the organic layer30 and is obtained closer to the side of the interference adjustmentlayer 50 than the organic layer 30, of the element D100-a and that ofthe element D114-a. Wavelength dependency cannot be seen in thereflectance of the element D100-a without the first layer 51 and thesecond layer 52. On the other hand, in the case of the element D114-a inwhich the coefficient B of the first layer 51 is 1.00, the reflectanceof the blue region improves because the peak wavelength of thereflectance becomes 442 nm by receiving the influence from the multipleinterferences of the interference adjustment layer 50. That is, byarranging the interference adjustment layer 50 on the organic layer 30,the resonant wavelength of the reflectance of light, which is emittedfrom the light emitting layer 32 of the organic layer 30 and is obtainedcloser to the side of the interference adjustment layer 50 than theorganic layer 30, will be 442 nm. Although this will increase theresonant intensity of the blue region of the element D114-a and the peakwavelength of emitted light will decrease to 480 nm, it will not reach450 nm. Hence, as shown in FIG. 21, the chromaticity of the B pixel willbe (u′, v′)=(0.150, 0.188), and the effect of chromaticity improvementof the B pixel by the interference adjustment layer 50 is small.

On the other hand, the interference condition of the element D114-baccording to the example of the embodiment is shown in FIG. 10. Thecoefficient B of the first layer 51 is 0.64, and the resonant wavelengthof the optical distance between the reflection surface 54 and thesemi-transmissive electrode 40 has a resonance closer to the shortwavelength side than the shortest wavelength λb=450 of the emitted lightof BD. Thus, the peak wavelength of the reflectance of light, which isemitted from the light emitting layer 32 of the organic layer 30 and isobtained closer to the side of the interference adjustment layer 50 thanthe organic layer 30, will be 425 nm or less, and the minimum value ofthe reflectance will fall in a range from 470 nm to 500 nm. Hence, theresonant wavelength of the whole element D114-b can be reduced to 450 nmfrom the resonant wavelength of 500 nm of the element D100-a which doesnot include the interference adjustment layer 50. Also, since theminimum value of the optical interference is present in the range from480 nm to 500 nm, it can be seen that bandwidth of the resonantintensity of the whole element will narrow in the blue region. As aresult, as shown in FIG. 21, the chromaticity of the B pixel of theelement D114-b becomes (u′, v′)=0.165, 0.160), and the chromaticity ofthe B pixel is improved. As a result of consideration by the inventors,it has been found that the chromaticity of the B pixel will improve whenthe resonant wavelength of the optical distance between thesemi-transmissive electrode 40 and the reflection surface 54, which isthe interface between the first layer 51 and the second layer 52 of theinterference adjustment layer 50 formed on the organic layer 30, becomesshorter than the wavelength λb. More specifically, it has been foundthat the above-described effect is enhanced when the resonant wavelengthof the organic layer 30 is 510 nm (inclusive) to 550 nm (inclusive), theresonant wavelength of the optical distance between the organic layer 30and the reflection surface 54 is 435 nm or less, and the minimum valueof the optical interference of the optical distance between the organiclayer 30 to the reflection surface 54 is 480 nm (inclusive) to 510 nm(inclusive).

As disclosed in Japanese Patent Laid-Open No. 2011-210677, in a case inwhich the film thicknesses of the first layer 51 and the second layer 52are set as (2m−1)λb/4 (m=0, 1, . . . ), the chromaticity of the B pixelis reduced in an element in which the value of the coefficient A of theorganic layer 30 is large in the manner of the element D114-a. On theother hand, in the embodiment, by reducing the coefficient B of thefirst layer 51, for example, by setting B<0.8 or less, it becomespossible to maintain the chromaticity of the B pixel even in each lightemitting element 10 whose coefficient A of the organic layer 30 islarge.

The refractive index of each layer of the interference adjustment layer50 according to the first embodiment will be described next. FIG. 11 isa graph showing the relationship between a refractive index differenceδ_(n12) and the coefficient A of the organic layer 30. In this case, therefractive index difference δn₁₂ is a difference (δn₁₂=n₁−n₂) betweenthe refractive index n₁ of the first layer 51 at the wavelength λb=450nm and the refractive index n₂ of the second layer 52 at the samewavelength λb=450 nm. The value of the coefficient A of the organiclayer 30 shown in FIG. 11 is a value of the light emitting element 10 inwhich the chromaticity v′ of the B pixel becomes 0.160 obtained from thePareto optimal solution. That is, it is the maximum value of thecoefficient A of the organic layer 30 of the light emitting element 10that can satisfy a state in which the chromaticity v′ of the B pixel is0.160.

In FIG. 11, in contrast to a state in which the refractive indexdifference δn₁₂ is 0 (that is, a condition in which the first layer 51and the second layer 52 are not arranged) and is near a state in whichthe coefficient A of the organic layer 30 is 1, it can be seen that thevalue of the coefficient A tends to increase as the refractive indexdifference δ_(n12) increases. In particular, the refractive indexδ_(n12) has an inflection point near 0.6, and the tilt increases in aregion in which δ_(n12)=0.6 or more. That is, this represents that theeffect of the introduction of interference adjustment layer 50 is moreeffective. As a result of consideration by the inventors, it has beenfound that setting δn₁₂>0.2 is sufficient as long as the coefficient Bof the first layer 51<0.9. In addition, it has been found that theeffect of the introduction of the interference adjustment layer 50 withthe multilayer structure can be further obtained by settingδ_(n12)≥0.58. Also, regarding the third layer 53, the refractive indexn₃ of the wavelength λb of the third layer 53 can be higher than therefractive index n₂ of the wavelength λb of the second layer 52 asdescribed above.

The reflective electrode 20 according to the first embodiment will bedescribed next. FIG. 12 shows the relationship between power consumptionand the refractive index difference δ_(n12) between the first layer 51and the second layer 52 in the Pareto optimal solution arrangementhaving the element arrangement of the light emitting element 10 shown inFIG. 11. In this case, multi-objective optimization is performed usingan objective function having two conditions of minimizing the powerconsumption and maximizing the coefficient A of the organic layer 30. Asthe constraint functions, the chromaticity of the R pixel is set tou′>0.45, the chromaticity of the G pixel is set to u′<0.13, and thechromaticity of the B pixel is set to 0.155≤v′≤0.165. Each plot of FIG.11 represents the power consumption in the element arrangement in whichthe chromaticity v′ of the B pixel is 0.160. That is, it is an elementarrangement in which the weighting of terms such as the coefficient A ofthe organic layer 30 is maximum and the power consumption is minimum isset to be 1:1. Each solid plot of FIG. 12 represents a case in which thereflective electrode 20 is an Al electrode, and each hollow plotrepresents a case in which the reflective electrode 20 is an Agelectrode.

From FIG. 12, it can be seen that, in a case in which the reflectiveelectrode 20 is an Ag electrode, the power consumption is about 80 mWeven in the light emitting element 10 with the high refractive index n₁of the first layer 51, and that the power consumption is higher than thecase in which the reflective electrode 20 is an Al electrode. Thisincrease in the power consumption is caused by the surface plasmon lossdue to the Ag electrode used as the reflective electrode 20. Morespecifically, this is because there is a large number wave differencebetween the surface plasmon of the Ag electrode used as the reflectiveelectrode 20 and the surface plasmon generated by the semi-transmissiveelectrode 40, and the electric field generated by the surface plasmon onthe light emitting layer 32 is increased. Hence, it can be said that anAl electrode which has a high plasmon frequency is more suitable to beused as the reflective electrode 20.

The analysis result of the second embodiment will be described next.First, the effect of the introduction of the first layer 51 and thesecond layer 52 will be described. Other than the fact that a simulationwas performed by using a dielectric as the first layer 51 and a metal(Ag) as the second layer 52, the same calculation as the methoddescribed in the first embodiment was performed in this analysis.

FIG. 13 shows each Pareto optimal solution of the coefficient A of theorganic layer 30 and a chromaticity v′ of a B pixel according to thesecond embodiment. In this case, to clarify the relationship between thecoefficient A of the organic layer 30 and the chromaticity v′ of the Bpixel in relation to the film thickness of the first layer 51, acalculation was performed by fixing exciton generation ratios γ_(b),γ_(g), and γ_(r) of BD, GD, and RD to 0.48, 0.28, and 0.24,respectively. FIG. 13 shows an above-described element D100 without thefirst layer 51 and the second layer 52 according to the comparativeexample and elements D201, D202, and D203 according to examples of thesecond embodiment. There are shown Pareto solutions of a case in whichthe refractive indices of the first layers 51 of the elements D201,D202, and D203 are 1.40, 1.99, and 2.40, respectively. As can beunderstood from FIG. 13, when a comparison is performed by setting thechromaticity v′ of the B pixel to 0.16, the coefficient A of the organiclayer 30 will be 1 in the element D100 according to the comparativeexample. In contrast, the coefficient A of the organic layer 30 is A≥1.4in the elements D201, D202, and D203 according to the examples of thesecond embodiment, and it can be seen that the effect of insertion of aninterference adjustment layer 50 with the multilayer structure is high.Based on the relationship between the coefficient A and the refractiveindex of the organic layer 30, the film thickness of the organic layer30 can be, for example, 85 nm or more or 90 nm or more. In addition, thefilm thickness of the organic layer 30 may be 100 nm or more. The yieldwhen each light emitting element 10 is manufactured can be improved byincreasing the film thickness of the organic layer 30.

FIG. 14 shows the coefficient C of the first layer 51 obtained fromequation (6) in the Pareto optimal solution arrangement of FIG. 13. Itcan be seen from FIG. 12 that the value of the coefficient C decreasesas the coefficient A of the organic layer 30 increases. That is, it hasbeen found that, in a case in which the film thickness of the organiclayer 30 becomes thicker than the λb/4 interference condition, it ispreferable to set the film thickness of the first layer 51 so that thefilm thickness of the first layer 51 will be smaller than the λb/2optical condition. In this embodiment, from the point of view of theyield, the coefficient C of the first layer 51 may be set to 0.8 or lessin a case in which the coefficient A of the organic layer 30 is set to1.2 or more. In addition, the coefficient C of the first layer 51 may beset to 0.75 or less in a case in which the coefficient A of the organiclayer 30 is set to 1.3 or more. Based on the relationship between thecoefficient C and the refractive index of the material to be used as thefirst layer 51 described above, the film thickness of the first layer 51may be 110 nm or less. The film thickness of the first layer 51 may alsobe 90 nm or less. Furthermore, the film thickness of the first layer 51may be 70 nm or less. In addition, the film thickness of the Ag layerforming the second layer 52 suffices to be 10 nm or more, and may fallwithin a range of 10 nm (inclusive) to 16 nm (inclusive) from the pointof view of the color reproduction range of the light emitting element10. Also, as shown in FIG. 18, the film thickness of the second layermay fall within the range of 8 nm (inclusive) to 17 nm (inclusive), andmay be appropriately determined within this range.

The effects of the second embodiment will be described next. FIG. 15shows the wavelength dependency of the resonant intensity of an elementD100-a according to a comparative example and that of an element D202-aaccording to an example of the second embodiment shown in FIG. 22. InFIGS. 15 and 22, a calculation was performed by setting the filmthicknesses of a hole injection transport layer 31, an electroninjection transport layer 33, and the semi-transmissive electrode 40 ofthe light emitting element 10 as 25 nm, 54 nm, and 10 nm, respectively.In this case, the coefficient A of the organic layer 30 will be 1.31.The refractive index n₁ of the first layer 51 of the element D202-a is1.98 when wavelength λb=450 nm, and the coefficient C of the first layer51 is 0.67. In this case, as shown in FIG. 22, the chromaticity of the Bpixel is (u′, v′)=(0.163, 0.162), and it can be said that the effect ofthe introduction of the interference adjustment layer 50 which has themultilayer structure including the first layer 51 and the second layer52 is being exhibited.

In a case in which the coefficient A of the organic layer 30 is 1, theresonant intensity between the reflective electrode 20 and thesemi-transmissive electrode 40 will have a peak intensity with respectto a light of the wavelength of 450 nm. However, as the coefficient Aincreases, the peak wavelength of the resonant intensity will increase,and this will strengthen light of a wavelength of about 512 nm when thecoefficient A is 1.31. A solid line shown in FIG. 15 represents thereflectance of light, which is emitted from the light emitting surfaceof BD of a light emitting layer 32 of the organic layer 30, obtained onthe side closer to the interference adjustment layer 50 than the organiclayer 30. In a case in which the coefficient C of the first layer 51 is1, the peak of the reflectance is generated near 450 nm. As shown inFIG. 15, in a case in which the coefficient C of the first layer 51 is0.67, the peak wavelength of light reflected by the semi-transmissiveelectrode 40 will shift to the short wavelength side and will be 400 nmor less. As a result, the resonant frequency, in the case in which thefirst layer 51 and the second layer 52 are arranged according to thisembodiment, will shift greatly to the short wavelength side, and thepeak wavelength will be 450 nm. Also, in the same manner as the caseaccording to the first embodiment shown in FIG. 10, the minimum value ofthe reflectance will be near 500 nm. Hence, the bandwidth of theresonant frequency of the element D202-a narrows in the blue region. Asa result, even in a case in which the film thickness of the organiclayer 30 has increased, the chromaticity v′ of the B pixel can bemaintained. That is, both the improvement in the reliability and thecolor reproducibility of the organic device 100 can also be implementedin the second embodiment.

In the second embodiment, if the first layer 51 satisfies thecoefficient C described above, the dependency of the refractive index ofthe first layer 51 with respect to the coefficient A of the organiclayer 30 will be low. However, in the second embodiment, due to the factthat the second layer 52 is a metal, the dependency of the refractiveindex of the first layer 51 will be exhibited with respect to the powerconsumption. An arrangement for further improving the characteristics ofthe second embodiment from the dependency of the refractive index of thefirst layer 51 shown in FIG. 16 will be described. FIG. 16 shows therelationship between the power consumption and the refractive index n₁of the first layer 51 in the Pareto optimal solution arrangementobtained in the range of FIG. 22. In this case, the multi-objectiveoptimization is performed by using the objective function having the twoconditions of minimizing the power consumption and maximizing thecoefficient A of the organic layer 30. As the constraint functions, thechromaticity of the R pixel is set to u′>0.45, the chromaticity of the Gpixel is set to u′<0.13, and the chromaticity of the B pixel is set to0.155≤v′≤0.165. Each plot of FIG. 16 represents the power consumption inthe element arrangement in which the chromaticity v′ of the B pixel is0.160. That is, it is an element arrangement in which the weighting ofterms such as the coefficient A of the organic layer 30 is maximum andthe power consumption is minimum is set to be 1:1. Each solid plot inFIG. 16 represents a case in which the reflective electrode 20 is an Alelectrode (Al/Ti stacked electrode), and each hollow plot represents acase in which the reflective electrode is an Ag electrode.

It can be seen that, in a case in which the reflective electrode 20 isan Ag electrode, the power consumption is about 80 mW even if the highrefractive index n₁ of the first layer 51 is set to 2.44, and that thepower consumption is higher than the case in which the reflectiveelectrode 20 is an Al electrode. This increase in the power consumptionis caused by the surface plasmon loss due to the Ag electrode used asthe reflective electrode 20. More specifically, this is because there isa large number wave difference between the surface plasmon of the Agelectrode used as the reflective electrode 20 and the surface plasmongenerated by the semi-transmissive electrode 40 and the second layer 52,and the electric field generated by the surface plasmon on the lightemitting layer 32 is increased. Hence, it can be said that an Alelectrode which has a high plasmon frequency is more suitable to be usedas the reflective electrode 20.

A case in which an Al electrode is used as the reflective electrode 20will be described next. In a case in which the Al electrode is used asthe reflective electrode 20, the power consumption will be lower thanthe power consumption of the case in which the Ag electrode is used asthe reflective electrode 20. Examining the dependency of the refractiveindex n₁ of the first layer 51 in the light emitting element 10 usingthe Al electrode as the reflective electrode 20, it can be seen that thepower consumption tends to increase as the refractive index n₁ decreasesin the manner of 58 mW, 64 mW, and 72 mW when the refractive index n₁ ofthe first layer 51 is 2.44, 2.00, and 1.60, respectively. Furthermore,the power consumption increase ratio will change at the refractive indexof 1.40, and the power consumption will be 86 mW when the refractiveindex n₁ of the first layer 51 is 1.40. That is, it can be seen fromFIG. 16 that the power consumption has an inflection point in a regionwhere the refractive index n₁ of the first layer 51 is near 1.6.

FIG. 17 shows the energy dissipation spectrum of the elements D201,D202, and D203 in a case in which the Al electrode (Al/Ti stackedelectrode) is the reflective electrode 20 of FIG. 16. The refractiveindices n₁ of the first layers 51 of the elements D201, D202, and D203are 1.40, 1.99, and 2.40, respectively, and each film thicknessarrangement was calculated to be a film thickness arrangement in whichthe chromaticity v′ of the B pixel will be 0.160. The abscissa is anormalized wavenumber and has been normalized by the wavenumber of thelight emitting layer 32, and a region which is 1 or more represents asurface plasmon loss.

FIG. 17 shows a surface plasmon mode referred to as TM-1 modes of theelements D201, D202, and D203. It is a mode obtained by antisymmetricbonding of a long-range surface plasmon (LRSP) generated in each of thesemi-transmissive electrode 40 and the second layer 52 and the surfaceplasmon generated by the Al electrode used as the reflective electrode20. It can be seen that the increase in the power consumption of theexample D201 shown in FIG. 16 is an increase in the TM-1 mode caused bythe low refractive index n₁ of the first layer 51.

In this manner, from the point of view of TM-1 mode suppression, it ispreferable for the refractive index n₁ of the first layer 51 to have alarge value as much as possible. In addition, it can be seen that, fromthe result shown in FIG. 16, a material which has a refractive index of1.6 or more and is higher than the inflection point of power consumptionmay be used as the first layer 51. Furthermore, from the point of viewof power consumption suppression, a material which has a refractiveindex of 1.9 or more may be used as the first layer 51.

Application examples in which the organic device 100 according to theembodiments is applied to any one of a display apparatus, an imagecapturing apparatus, a portable device, an illumination apparatus, and amoving body will be described hereinafter with reference to FIGS. 23 to28. FIG. 23 is a schematic view showing an example of a displayapparatus using the organic device 100 according to the embodiments. Adisplay apparatus 1000 can include a touch panel 1003, a display panel1005, a frame 1006, a circuit substrate 1007, and a battery 1008 betweenan upper portion cover 1001 and a lower portion cover 1009. Flexibleprint circuits FPC 1002 and 1004 are connected to the touch panel 1003and the display panel 1005. An active element such as a transistor orthe like is arranged on the circuit substrate 1007. The battery 1008need not be arranged unless the display apparatus 1000 is a portabledevice, and need not be arranged in the position even if the displayapparatus is a portable device. The above-described organic device 100that functions as a light emitting apparatus by including the organiclayer 30 which includes an organic light emitting material, such asorganic EL, can be used as the display panel 1005. The organic device100 that functions as the display panel 1005 operates by being connectedto an active element such as a transistor or the like arranged on thecircuit substrate 1007.

The display apparatus 1000 shown in FIG. 23 may be used as a displayunit of an image capturing apparatus that includes an optical unitincluding a plurality of lenses and an image capturing elementconfigured to receive light that passed through the optical unit. Theimage capturing apparatus can include a display unit for displayinginformation obtained by the image capturing element. The display unitcan also be a display unit exposed outside the image capturing apparatusor a display unit arranged inside the viewfinder. The image capturingapparatus may be a digital camera or a digital video camera.

FIG. 24 is a schematic view showing an example of an image capturingapparatus using the organic device 100 according to the embodiments. Animage capturing apparatus 1100 can include a viewfinder 1101, a backsurface display 1102, an operation unit 1103, and a housing 1104. Theabove-described organic device 100 that functions as a light emittingapparatus by including the organic layer 30 which includes an organiclight emitting material can be used as the viewfinder 1101 which is adisplay unit. In this case, the organic device 100 may not only displayan image to be captured, but also environment information, an imagecapturing instruction, and the like. The environment information may beinformation of the intensity of natural light, the direction of thenatural light, the speed of the movement of an object, the possibilitythat the object is shielded by a shielding object, and the like.

Since the timing suitable for image capturing frequently tends to be ashort period of time, it is preferable to display information as quicklyas possible. Hence, the above-described organic device 100 including theorganic layer 30 which includes an organic light emitting material canbe used as the viewfinder 1101. This is because an organic lightemitting material has a high response speed. The organic device 100using an organic light emitting material can be used more suitably, thana liquid crystal display apparatus, for these apparatuses that requirehigh display speed.

The image capturing apparatus 1100 includes an optical unit (not shown).The optical unit includes a plurality of lenses, and forms an image onan image capturing element (not shown) that receives light that passedthrough the optical unit and is contained in the housing 1104. The focalpoints of the plurality of lenses can be adjusted by adjusting theirrelative positions. This operation can be performed automatically.

The above-described organic device 100 that functions as a lightemitting apparatus by including the organic layer 30 which includes anorganic light emitting material can be used as a display unit of aportable device. In this case, the organic device may have both adisplay function and an operation function. The mobile device can be amobile phone such as smartphone or the like, a tablet, a head-mounteddisplay, or the like.

FIG. 25 is a schematic view showing an example of a portable deviceusing the organic device 100 according to the embodiments. A portabledevice 1200 includes a display unit 1201, an operation unit 1202, and ahousing 1203. The housing 1203 can include a circuit, a printed boardwhich includes the circuit, a battery, and a communication unit. Theoperation unit 1202 can either be a button or a touch-panel-typereaction unit. The operation unit 1202 can also be a biometricauthentication unit that performs unlocking or the like byauthenticating a fingerprint. A portable device including acommunication unit can also be regarded as a communication apparatus.The above-described organic device 100 that functions as a lightemitting apparatus by including the organic layer 30 which includes anorganic light emitting material can be used as the display unit 1201.

FIGS. 26A and 26B are schematic views showing examples of a displayapparatus using the organic device 100 according to the embodiments.FIG. 26A shows a display apparatus such as a television monitor or a PCmonitor. A display apparatus 1300 includes a frame 1301 and a displayunit 1302. The above-described organic device 100 that functions as alight emitting apparatus by including the organic layer 30 whichincludes an organic light emitting material can be used as the displayunit 1302. The display apparatus 1300 may also include a base 1303 thatsupports the frame 1301 and the display unit 1302. The base 1303 is notlimited to the form shown in FIG. 26A. For example, the lower side ofthe frame 1301 may also function as the base 1303. In addition, theframe 1301 and the display unit 1302 can be bent. The radius ofcurvature in this case can be 5,000 mm (inclusive) to 6,000 (inclusive)mm.

FIG. 26B is a schematic view showing another example of the displayapparatus using the organic device 100 according to the embodiments. Adisplay apparatus 1310 shown in FIG. 26B can be folded, that is, thedisplay apparatus 1310 is a so-called foldable display apparatus. Thedisplay apparatus 1310 includes a first display unit 1311, a seconddisplay unit 1312, a housing 1313, and a bending point 1314. Theabove-described organic device 100 that functions as a light emittingapparatus by including the organic layer 30 which includes an organiclight emitting material can be used as each of the first display unit1311 and the second display unit 1312. The first display unit 1311 andthe second display unit 1312 can be one seamless display device. Thefirst display unit 1311 and the second display unit 1312 can be dividedfrom the bending point. The first display unit 1311 and the seconddisplay unit 1312 can display different images and can also display asingle image together.

FIG. 27 is a schematic view showing an example of the illuminationapparatus using the organic device 100 according to the embodiments. Anillumination apparatus 1400 can include a housing 1401, a light source1402, a circuit board 1403, an optical film 1404, and a light diffusingunit 1405. The above-described organic device 100 that functions as alight emitting apparatus by including the organic layer 30 whichincludes an organic light emitting material can be used as the lightsource 1402. The optical film 1404 can be a filter that improves thecolor rendering of the light source. The light diffusing unit 1405 canlight up or the like to deliver the light of the light source over abroad range by effectively diffusing the light. The illuminationapparatus 1400 can also include a cover on the outermost portion. Theillumination apparatus 1400 may include both the optical film 1404 andthe light diffusing unit 1405 or may include only one of thesecomponents.

The illumination apparatus 1400 is an apparatus for illuminating a roomor the like. The illumination apparatus 1400 can emit white light,natural white light, or light of any color from blue to red. Theillumination apparatus 1400 can also include a light control circuit forcontrolling these light components. The illumination apparatus 1400 canalso include a power supply circuit to be connected to the organicdevice 100 that functions as the light source 1402. The power supplycircuit can be a circuit for converting an AC voltage into a DC voltage.“White” has a color temperature of about 4,200 K, and “natural white”has a color temperature of about 5,000 K. The illumination apparatus1400 may also have a color filter. In addition, the illuminationapparatus 1400 can have a heat radiation unit. The heat radiation unitradiates the internal heat of the apparatus to the outside of theapparatus, and examples are a metal having a high specific heat andliquid silicon.

FIG. 28 is a schematic view of an automobile including a taillight as anexample of a vehicle lighting device using the organic device 100according to the embodiments. An automobile 1500 has a taillight 1501,and the taillight 1501 is turned on when a braking operation or the likeis performed. The organic device 100 according to the embodiments mayalso be used as a headlight as a vehicle lighting device. The automobileis an example of a moving body, and the moving body can be a ship, adrone, an airplane, a railway vehicle or the like. The moving body caninclude a main body and a lighting device installed in the main body.The lighting device may also be an apparatus that notifies the currentposition of the main body.

The above-described organic device 100 that functions as a lightemitting apparatus by including the organic layer 30 which includes anorganic light emitting material can be used as the taillight 1501. Thetaillight 1501 can have a protection member for protecting the organicdevice 100 that functions as the taillight 1501. Although the materialof the protection member is not limited as long as it is a transparentmaterial with a high degree of strength to a certain extent, it may bemade of polycarbonate or the like. The protection member can also beformed by mixing a furandicarboxylic acid derivative or an acrylonitrilederivative in polycarbonate.

The automobile 1500 can include a vehicle body 1503 and a window 1502attached to the vehicle body 1503. This window can be a window forchecking the front and rear of the automobile, and can also be atransparent display. The above-described organic device 100 thatfunctions as a light emitting apparatus by including the organic layer30 which includes an organic light emitting material can be used as thistransparent display. In this case, the constituent materials such as theelectrodes of the organic device 100 are formed by transparent members.

According to the present invention, a technique advantageous inimproving both the reliability and the color reproducibility of anorganic device can be provided.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2019-087724, filed May 7, 2019 which is hereby incorporated by referenceherein in its entirety.

What is claimed is:
 1. An organic device comprising a reflectiveelectrode configured to reflect light, an organic layer arranged on thereflective electrode, a semi-transmissive electrode arranged on theorganic layer, and a reflection surface formed above thesemi-transmissive electrode, wherein the organic layer emits white lightand includes a light emitting layer configured to emit blue light,wherein an optical distance L of the organic layer satisfies:L≥[{(ϕr+ϕs)/π}×(λb/4)]×1.2, where λb [nm] is a peak wavelength ofemitted light of a blue light emitting layer, ϕr [rad] is a phase shiftamount of the light of the wavelength λb in the reflective electrode, ϕs[rad] is a phase shift amount of the light of the wavelength λb in thesemi-transmissive electrode, and wherein a resonant wavelength of anoptical distance between the semi-transmissive electrode and thereflection surface is shorter than the wavelength λb.
 2. An imagecapturing apparatus comprising: an optical unit that includes aplurality of lenses; an image capturing element configured to receivelight that passed through the optical unit; and a display unitconfigured to display an image, wherein the display unit is a displayunit that displays an image captured by the image capturing element andincludes the organic device according to claim
 1. 3. An illuminationapparatus comprising: a light source; and at least one of a lightdiffusing unit and an optical film, wherein the light source includesthe organic device according to claim
 1. 4. A moving body comprising: abody; and a lighting device arranged on the body, wherein the lightingdevice includes the organic device according to claim
 1. 5. A displayapparatus comprising: the organic device according to claim 1; and anactive element connected to the organic device.
 6. The device accordingto claim 1, wherein the reflective electrode does not contain silver. 7.The device according to claim 1, further comprising: an interferenceadjustment layer arranged on the semi-transmissive electrode, whereinthe interference adjustment layer includes a first layer, a second layerarranged on the first layer, and a third layer arranged on the secondlayer, wherein each of the first layer and the third layer is made of adielectric, wherein the second layer is made of a metal, and wherein anoptical distance L1 of the first layer satisfies:L1≤(λb/2)×0.8.
 8. The device according to claim 7, wherein the opticaldistance L of the organic layer satisfies:L≥[{(ϕr+ϕs)/π}×(λb/4)]×1.3, and the optical distance L1 of the firstlayer satisfies:L1≤(λb/2)×0.7.
 9. The device according to claim 7, wherein a filmthickness of the organic layer is not less than 90 nm, and wherein afilm thickness of the first layer is not more than 90 nm.
 10. The deviceaccording to claim 1, further comprising: an interference adjustmentlayer arranged on the semi-transmissive electrode, wherein theinterference adjustment layer includes a first layer, a second layerarranged on the first layer, and a third layer arranged on the secondlayer, and wherein each of the first layer, the second layer, and thethird layer is made of a dielectric.
 11. The device according to claim10, wherein the optical distance L of the organic layer satisfies:≥L[{(ϕr+ϕs)/π}×(λb/4)]×1.35, and wherein an optical distance L1 of thefirst layer satisfies:L1≤(λb/4)×0.75.
 12. The device according to claim 10, wherein a resonantwavelength of the organic layer is 510 nm to 550 nm, wherein a resonantwavelength of an optical distance between the organic layer and thereflection surface is not more than 435 nm, and wherein a minimum valueof optical interference of the optical distance between the organiclayer and the reflection surface is 480 nm to 510 nm.
 13. The deviceaccording to claim 10, wherein a refractive index of the wavelength λbof the third layer is higher than the refractive index of the wavelengthλb of the second layer.
 14. The device according to claim 10, wherein arefractive index of the wavelength λb of the first layer is higher thana refractive index of the wavelength λb of the second layer.
 15. Theorganic device according to claim 10, wherein the first layer isarranged on the semi-transmissive electrode, wherein a film thickness ofthe organic layer is not less than 90 nm, and wherein a film thicknessof the first layer is not more than 40 nm.
 16. The device according toclaim 10, wherein a refractive index of the wavelength λb of the thirdlayer is not less than 1.9.
 17. The device according to claim 10,wherein a film thickness of the organic layer is not less than 85 nm,and wherein a film thickness of the first layer is not more than 50 nm.